Logic Pro 9 Core Audio and Disk Overloads a Plenty


Hello All!

After struggling alone for a month or so I have finally (Like a male driver hopelessly lost in an unfamiliar part of the countryside) realised that i need to ask for help! I consider myself fairly clued up with Logic and mac audio in general (heavy user since 4.8) but this issue has really confounded me.

I run Logic pro (9.1.8 but the problem was with me from 9.1.7) on a mid 2011 27" iMac (Processor 3.4 GHz Intel Core i7, Memory 8 GB 1333 MHz DDR3, Graphics AMD Radeon HD 6970M 1024 MB, Software OS X 10.8.2 (12C60), but i also had this problem with 10.7.latest) with all software updates installed. My interfaces are 2xMH 2882's (both 2D one with dsp) and an M-audio profire 2626 running the latest drivers. I have a Lacie D2 (with a 120Gb SSD cludged in there wired through a sonnet TB->express card->FW800) and a drobo 5D via TB.

In almost every project i run i get disk overloads and core audio type overloads (typically when entering a chorus or when more audio tracks start) even with 3/4 audio tracks (48/24) this problem persists, I've tried changing buffer settings, I've tried shifting projects to different drives (including the internal 7200 iMac drive) clean reinstalling and slowly working my way through previously known working versions of OSX and Logic but to no avail. After failing to get the hardware diagnostics running on the iMac i took it into my local apple store (thankfully just around the corner, not as easy to carry about as my MBP!) where they ran a loop diagnostic overnight, with no faults found. I should say this system *used* to work just fine, unfortunately I was extremely busy in the studio when this started occurring and my only recourse was to move back to my 17" MBP (2009) and I honestly can't recall if i did/installed anything when this started occurring. I've exhausted my troubleshooting routines and the patience of my local apple store. The time has come where i need to man up and defer to the esteemed LUG!

I hope i've given you guys all the facts you need, I'd almost be happier to get a crash out and hence a diagnostic report to see where its failing. I've opened up the console to monitor for error messages but don't see any. The cpu and HD meters seem to bumble about at the bottom of the range and then spontaneously peak.

Any help or advice will be much appreciated!

All the best, Mike
Hard to say for sure, but look at three things. I'm sure others will have ideas as well.

Are you running Logic in 32 bit mode? If so, that 8 gigs of RAM is not being used.

Are you cramming a bunch of processor intensive instruments and plug-ins on one channel strip? Everything on a given channel strip is processed by one processor.

Make sure your external drive is format for a Mac, not a PC.
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I would suggest this:

Use 1 test song, one that this issue happens with, for the following:

Step 1) Copy your song to your internal drive (just for this test). Remove all external drives. Play session. Is it still happening? No, it's one of your external drives. Add one back, redo test, add the other back, redo test. You should discover which drive is the issue. Yes, go on to next step.

Step 2). Go back to the original test session on your external drive. Bounce all virtual instruments to disc. Are you still getting overloads? No: you are using too many VI's and need to bounce some to disc. Yes, go on to next step.

Step 3). Mute all tracks both ways: the regions AND the track. This should bypass all DSP. Unmute one track at a time and then run song. When does the overload happen? If you re-mute that track and continue to the next track, does it still overload?

These would be the first 3 steps I would take trying to problems solve this type of issue. Please let me know what your results are after doing each one, and we can continue if needed.
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Hi all and thanks for the suggestions!
Doug, I've tried 32 and 64 bit modes (I presume you mean the "Get Info" parameter) to no avail. My "always f***s up track" (the one I've picked that consistently fails) has about 5/6 mh channelstrips a space designer a couple of psp neons (mix version, ie lowest CPU hit) and a couple of sonnox de-essers, it runs fine on my old mbp (2009 17" 2.9 core duo 2) and similar (and more intensive) always ran fine in the past. My HDs are all HTFS with the exception of my boot camp partition which is on the macs internal drive (I don't use this drive for audio)

George, I'll give this a go and let you know what happens!

Thanks for all the help and I'll keep you all posted!

All the best, Mike
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Hi George, I've finally had enough down time to start on your suggestions (I have to make hay while the sun shines!) So far I've only got to step 1. I've found that the project doesn't cr@p out if running from my LaCie SSD but the peaks are still visible, I think it's the raw speed of the ssd that does it, the meters still spontaneously shoot up but the system doesn't stop. To my mind it seams like something isn't caching properly, don't know wether it's logic, core audio (or driver) or plugins yet. I'm scanning the console but can't find any seemingly pertinent messages. When I have some more time i'll start narrowing this down to find the culprit!

All the best and thanks everyone for your help, Mike
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I note from your first post that you are using two MH 2882's as well as M-Audio's Profire. If you are using these as an aggregate audio device, I suggest trying the following:

Use just one 2882. Try it with various Buffer I/O settings. If that works, then try both 2992's without the profire. With an aggregate device, you may find that a higher Buffer I/O setting is required.

kind regards

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Hi and thanks for the suggestions! Although I do have a few "legacy" plugins installed, I didn't when the problem erupted, I do need to go through disabling and re-enabling all my AUs in sequence again to find if one of them is the problem this is my current thinking of the problem source

I don't actually have any aggregate devices, if I need 16+ channels I route the mios (via Adat) into the 2626 and have that as my audio driver (it has 26, "ins" and 2 sets of Adat,) but most of the time I just use the 2882s linked together (again via Adat) and my 1st 2882 is the driver selected in logic's audio prefs. I will definitely have a look at disconnecting and then reordering the interfaces and trying each, but it's a bit of a jungle back there so i wont have a chance for a bit!

Thanks again for everyone's help, this is precisely why I came to you guys, it's all about experience! If anyone has experienced or successfully battled a problem like this before please let me know. Although its currently running, it feels like a 5 litre V8 stuck in an original fiat 500 body yet still getting the performance of the 1/2 litre engine and it barely makes it up the smallest hill!

All the best, Mike
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I hesitated for a long, long time, then finally broke down and bought RAM from one of the third-party vendors. (Never get it from Apple. They overcharge.)

My machine as a whole is much, much snappier and, like I said, the overloads disappeared.
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Well I didn't realise how cheap the dimms are, for £45 I can get up to 16GB (2x4GB), so I'm going for it! Is there any consensus here over brand? Transcend and Crucial are readily available here.
Thanks, Mike
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From your post it sounds like you have a normal overload, nothing to do with your system.

Try freezing one track with plug-ins at a time. See where the meters start to "calm down", that should lead you to the problem child.
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Hi George, I strongly suspect your right, but it gives me an opportunity to rule out one more thing *and* I can offset many more disk streamed samples to memory I use EWQLSO Play quite a bit and I'm sure I'll be able to get a good few more instruments running before having to freeze. For £37 it's worth it to me!
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